Isoxazole and crotonamide derivatives having antiinflammatory, immunosuppressant, or antiproliferative action have been disclosed (EP 0 013 376; EP 0 217 206; EP 0 527 736). The analytical determination of these compounds in animal and human sera is possible with the aid of conventional chromatographic processes. The disadvantage of these chromatographic processes is a high outlay in terms of apparatus, complicated sample preparation steps and low sample throughput.
Immunological determination and analysis processes are a rapid and reliable alternative to chromatographic processes. The production of suitable antibodies is crucial for carrying out these alternative processes.